全文获取类型
收费全文 | 1322篇 |
免费 | 23篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 12篇 |
综合类 | 2篇 |
化学工业 | 185篇 |
金属工艺 | 33篇 |
机械仪表 | 38篇 |
建筑科学 | 30篇 |
矿业工程 | 3篇 |
能源动力 | 15篇 |
轻工业 | 124篇 |
水利工程 | 5篇 |
石油天然气 | 6篇 |
无线电 | 77篇 |
一般工业技术 | 129篇 |
冶金工业 | 539篇 |
原子能技术 | 12篇 |
自动化技术 | 137篇 |
出版年
2022年 | 9篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 47篇 |
2012年 | 30篇 |
2011年 | 28篇 |
2010年 | 35篇 |
2009年 | 31篇 |
2008年 | 49篇 |
2007年 | 41篇 |
2006年 | 35篇 |
2005年 | 27篇 |
2004年 | 42篇 |
2003年 | 38篇 |
2002年 | 28篇 |
2001年 | 36篇 |
2000年 | 27篇 |
1999年 | 39篇 |
1998年 | 99篇 |
1997年 | 67篇 |
1996年 | 57篇 |
1995年 | 40篇 |
1994年 | 27篇 |
1993年 | 47篇 |
1992年 | 35篇 |
1991年 | 21篇 |
1990年 | 15篇 |
1989年 | 25篇 |
1988年 | 14篇 |
1987年 | 25篇 |
1986年 | 23篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 10篇 |
1978年 | 14篇 |
1977年 | 16篇 |
1976年 | 20篇 |
1975年 | 9篇 |
1974年 | 9篇 |
1973年 | 6篇 |
1969年 | 6篇 |
排序方式: 共有1347条查询结果,搜索用时 359 毫秒
1.
P. J. C. Skitt M. A. Javed S. A. Sanders A. M. Higginson 《Journal of Intelligent Manufacturing》1993,4(1):79-94
The potential of using artificially simulated neural networks as intelligent, adaptive process-monitoring devices is discussed. The investigation is considered as a method for automatic, intelligent exception reporting for quality control applications. The technique is also compared with the conventional statistical approaches of principal component analysis and Kohonen's feature map. The applications of the technique in aerospace and manufacturing environments are presented and a possible extension of the method to incorporate a diagnostic function is discussed.Seconded from Cheltenham and Gloucester College of Higher Education as a Royal Society/SERC Research Fellow at Smith's Industries Aerospace and Defence Systems, Bishop's Cleeve, Cheltenham, UK. 相似文献
2.
3.
4.
M. Djaeni P. Bartels J. Sanders G. van Straten A. J. B. van Boxtel 《Drying Technology》2007,25(6):1053-1067
This work discusses the potential of three multistage zeolite drying systems (counter-, co-, and cross-current) with a varying number of stages. The evaluation showed that for 2-4 stages with heat recovery the efficiency of the systems ranges between 80 and 90%. Additionally, by introducing a compressor, the latent heat in the exhaust air from the regenerator is recovered and used to heat the inlet air for an additional drying stage. As a result, for the counter-current drying system and compressor pressure 1.5-2 bar, a maximum energy efficiency of 120% is achieved, which results in halving the energy consumption compared to conventional drying systems. 相似文献
5.
According to a 1991 study of sexual behavior based on a random sample of heterosexual undergraduates at a Midwestern university, 80% of the males and 73% of the females had experienced vaginal or anal intercourse. The average age at first vaginal intercourse was 17.2 years for both sexes. Seventeen percent of the sexually experienced males and 18% of the sexually experienced females had engaged in heterosexual anal intercourse; among these respondents, the average age at first anal intercourse was 20.3 for males and 19.1 for females. Although less than four years, on average, had elapsed since the respondents had first had vaginal intercourse, males reported an average of 8.0 lifetime vaginal-sex partners and females reported an average of 6.1. Overall, the findings from this random sample of students are similar to those from a 1988 convenience sample of the same college population. 相似文献
6.
Limited past studies have indicated that Si3 N4 doped with Sc2 O3 may exhibit high-temperature mechanical properties superior to Si3 N4 systems with various other oxide sintering additives. High-temperature deformation of this system was studied by characterizing the microstructures before and after deformation. It was found that elements of the additive, Sc and O, exist in small amounts at thin grain boundary layers and within secondary phases at triple and multiple grain boundary junctions. The secondary phase is devitrified as crystalline Sc2 Si2 O7 . Deformation of the samples was dominated by cavitation rather than dislocation processes. Thus, the excellent deformation resistance of the samples at high temperature can be attributed to the high refractories and enhanced crystallization of a secondary phase. 相似文献
7.
The pressure-flow (P-F) relationship in intravenous catheters is shown to be represented by the predictive model P = RLF + RTF2. The pressure loss due to F, calculated from experimental data, was found to equal the expected Poiseuille laminar flow loss. Pressure loss due to F2 was found to be the sum of turbulent P losses due to entrance length flow disturbance, kinetic energy at the outflow, and minor shape change losses. Analysis of the flow capabilities of intravenous catheters can be used to evaluate suitability for specific intravenous infusion needs. 相似文献
8.
Reinisch June M.; Sanders Stephanie A.; Ziemba-Davis Mary 《Canadian Metallurgical Quarterly》1988,43(11):921
To create the behavior-change programs essential for limiting the acquired immune deficiency syndrome (AIDS) epidemic, we must obtain a precise understanding of the sexual behavior, knowledge, and attitudes of our nation's various ethnic, racial, social, age, regional, and sexual orientation groups. Such information is necessary for developing the precisely targeted educational programs that currently are our most effective means of reducing risk behaviors and halting the spread of the disease in the United States. These behavioral data are also crucial to biomedical investigations, making possible the identification of appropriate subjects for programs ranging from the testing of vaccines to the evaluation of the threat to pregnant women and their offspring. In this article, we summarize data on sexual behaviors associated with the transmission of the AIDS virus (i.e., human immunodeficiency virus [HIV]) and discuss selected issues relevant to the conduct of research on human sexuality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
Examined perceived environment, perceived incentive and outcome, and person constructs for relationships with interest and participation in voluntary learning and development activity by nonmanagement employees. All 3 groups of constructs were related to development activity. In relationships with development activity, perceived outcome and environment variables interacted with workers' personal values relevant to aspects of a development setting, illustrating the potentially important role that differences in values may play in a development context. Additionally, small relationships were observed between several demographic variables and values within a development setting. Results provide implications for the design and implementation of successful development programs and highlight the need to carefully consider individual differences in this context when targeting many different types of employees for participation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.